Impact Study of Isolated and Correlated Manufacturing Tolerances of a Permanent Magnet Synchronous Machine for Traction Drives

In the course of a growing market share of electrified vehicles, electrical machines will be manufactured in a large scale. The production of high quantities leads to a scattering of the final geometries of e.g. the electrical steel sheets or bearing arrangements. Additionally, the dimensions, mountings and magnetic properties of permanent magnets are subjected to tolerances. This affects both, the electromagnetic and mechanical properties, as well as the acoustic behavior of the machines and therefore the operational behavior of the electrical drive in terms of acoustic emission and driving ability. For the initial analysis, finite-element simulation models are used to take non-linearities, e.g. saturation effects, into account. The purpose of this work is to analyze on the one hand the impact of correlated tolerances to identify tolerance combinations that enhance or weaken each other. On the other hand, isolated tolerances are studied to evaluate the impact on the considered target quantity. Random distributed asymmetric tolerances and eccentricities are simulated based on the tolerance analysis.